CINCINNATI -- Before the fading Reds opened their four-game series vs. the Nationals on Thursday night, manager David Bell expressed his hope that it would be the beginning of an against-the-odds charge to catch the Cardinals for the final National League playoff spot.

“For us, the focus of the last 10 days is to absolutely leave it all on the field and finish as strong as we possibly can,” Bell said pregame. “We’ll see where we end up. Obviously, we can’t control the Cardinals because we don’t play them anymore.”

But that charge did not begin as the Reds' offensive spark was too little, too late during a 3-2 defeat to the Nationals -- Cincinnati’s eighth loss in its last 11 games and 16th out of the last 23 in what’s been a stunning slide. Earlier in the day, the Cardinals won their 12th consecutive game in a win over the Brewers.

That left the Reds (78-75) trailing the Cardinals (83-69) by 5 1/2 games for the second NL Wild Card berth with nine games remaining. Cincinnati was also passed by Philadelphia, which is now 4 1/2 games back.

“It has been a little bit difficult seeing how the results have been,” Reds starting pitcher Luis Castillo said via translator Jorge Merlos. “You have to learn how to lose, and you have to learn how to win too. For us, I know we’re going to keep going and finish strong. It’s like a destiny that God has put us in. I know we’re a great team and we’re going to finish strong at the end of the season.”

Castillo moved into the Major League lead with his 16th loss of the season, surpassing opposing starter Patrick Corbin. Castillo pitched six innings and allowed two runs on six hits with three walks and six strikeouts.

Corbin’s 5.92 ERA is worst in the Majors this season but he silenced the Reds with 6 2/3 scoreless innings while giving up four hits and four walks.

For Cincinnati, there were missed chances to score against Corbin. The biggest chance came in the second inning when the Reds had the bases loaded after an error and a pair of one-out walks. But Corbin struck out both Nick Castellanos and Joey Votto to escape unscathed.

“You get into that situation, you want them at the plate,” Bell said. “We'll continue to want them at the plate. But even the best -- [a] couple of the best hitters in the game, it's not going to happen every time. That's why it's such a tough game. I know that they want to be back in that spot tomorrow and I can't wait until we're in that spot again because they're a couple of the best in the game.”

A one-out infield single by Lane Thomas against Castillo in the third inning led to a run. Juan Soto hit a two-out single and Josh Bell followed with an RBI single for the game’s first run. Leading off the sixth inning, Soto hit an 0-2 Castillo pitch to the first couple of rows of seats in left field for a home run.

“It was a two-seamer that I throw, which the pitch is supposed to start inside and land on the corner, but obviously it didn’t land there tonight,” Castillo said. “He was able to get a good swing on it and hit it out."

In the seventh inning with two outs against reliever Luis Cessa, Soto struck again with another solo homer -- his 29th -- which landed just inside the left-field foul pole to make it a three-run game.

The Reds' offense came to life in the bottom of the ninth inning against closer Kyle Finnegan. Eugenio Suárez led off with a single lined into center field and pinch-hitter Max Schrock ended the Washington bid for a combined shutout with an RBI triple to right field. Schrock scored on pinch-hitter Tucker Barnhart’s groundout that narrowed the deficit to one run.

On a full count with two outs, Finnegan hit Jonathan India on the hand with a pitch to put the tying run on first base. But Tyler Stephenson struck out to end the game to continue a discouraging final month of the regular season for the Reds.

“It's disappointing, frustrating every time we lose,” Bell said. “We know all these games are must-wins -- they will be the rest of the way. Then each day we come out with the intent of winning a baseball game and our players know where we are and they continue to prepare that way. When it hasn't worked out and we've lost the games, it's difficult. It's a bad feeling. Then we've got to come back tomorrow and keep playing. We have to. And this team will."